Road and rail vehicles have been developed that can travel on automotive roadways and also on fixed rails of a railroad track, or railways. Such vehicles are often used by railroad maintenance crews who may have to travel a distance on a regular roadway and an additional distance on a railway in order to reach a section of railroad track needing maintenance. These road and rail vehicles can also be useful in moving railcars in a switchyards because they are not stuck on the rails as are locomotive engines, but instead they can move cars on one rail line and then drive off the rail line, across the tracks to a different rail line without having to stay on the rails and use a switch to move to a different rail line.
Road and rail vehicles are often designed with two sets of wheels: a rubber based set of wheels for traveling on a roadway and a set of steel wheels for traveling on the tracks of a railway. On such road and rail vehicles one of the sets of wheels is retractable such that when the vehicle is on the roadway the rubber wheels can engage the ground and propel the vehicle, and when the vehicle is on a railway, the steel wheels can engage the rails to guide the vehicle on the track and to propel the vehicle. Other road and rail vehicles use the rubber wheels to propel the vehicle on both the roadway and the railway.
Road and rail vehicles can also be used to move railcars in place of a larger more expensive locomotive engine, thereby freeing the locomotive engine to move larger payloads. However, it will be appreciated that railcars can be considerably heavier than the road and rail vehicle and the weight of the railcar on the hitch of the road and rail vehicle can pivot the vehicle about the rear axle thereby reducing traction on the drive wheels. Consequently, it is sometimes desirable to place weights on a cargo bed of the road and rail vehicle so as to properly distribute weight along the frame of the vehicle in relation to the railcar being towed. This weighting of the road and rail vehicle helps to maintain contact between the wheels of the road and rail vehicle and the fixed rails of the railway. Without this extra loading the wheels can be lifted off the rails by the weight of the railcar, and the road and rail vehicle can loose tractive force for towing the railcar.
Unfortunately, loading the weights onto the cargo bed is not always possible. Lifting equipment is often needed to place the load onto the cargo bed of the road and rail vehicle. Such lifting equipment is often unavailable or impractical to use in a switch yard or on a remote rail line. Additionally, weights suitably heavy to counterbalance the weight of the railcar are not always readily available especially when the road and rail vehicle is being used on a remote railway.